The investigators focus on the visual motion processing system was initially motivated by the finding that many schizophrenic patients and their biological relatives have impaired smooth pursuit, but other kinds of eye movements are normal. The selectiveness of eye tracking dysfunction suggested possible involvement of the cortical motion processing systems in schizophrenia. The investigators recent studies have shown that motion processing is indeed compromised in schizophrenia. In this application, the investigators propose to extend the study of motion processing systematically and parametrically in relation to schizophrenia. The goals are to assess motion processing and its roles at different levels of visual, cognitive and motor processing. In a series of studies, we propose to examine various aspects of motion processing, including velocity discrimination, both detection of and smooth pursuit responses to coherent motion, and perceptual grouping of motion-based signals for object recognition in schizophrenia patients. The motion-related visual, cognitive and oculomotor tasks serve as probes into the neural activities of the motion-sensitive brain areas, such as Middle Temporal Area and Medial Superior Temporal Area, as well as the brain areas that use motion| information (such as those in the parietal lobe). The results of these studies will generate a systematic characterization of the functional properties of the motion processing system as well as the parietal system in schizophrenia.